Apparatus for concentrating ores



Man-eh 29, 1960 N. H. A. RODMAN PPARATUS FOR conczu'mnuc ORES Filed Jan. 8. 195a FIG.1

FIG. 4

United States Patent APPARATUS FOR CONCENTRATING ORES Norman H. A. Rodman, Virginia, Minn., assignor, by

mesne assignments, to Oreclone Concentratin Corporation, New York, N.Y., a corporation of New York Application January 8, 1958, Serial No. 707,824

9 Claims. (Cl. 209-430) This invention relates to separation and concentration of material and, more particularly, to a novel method and novel apparatus for concentrating ore by eflciently separating undesired tailings therefrom.

In the concentration of minerals, such as cores, for example, a known procedure is to sluice the crushed or ground ores with water flowing over a rifled bed. This washes away the lighter components leaving the heavier components to settle against the rifles. The rifled bed may be inclined so that the tailings will flow down by gravity, and a known procedure is to provide an inclined endless conveyor having the rifles on its outer surface. By this arrangement, as the tailings are washed downwardly for disposal or recirculation, the concentrates are carried upwardly for discharge into a receiver.

In known concentrating conveyors of this type, the rifles have extended substantially the full width of the conveyor so that the tailings are washed over successive rifles in a downward direction. This results in the tailings separated from the charge above each rifle being washed over the charges above each succeeding rifle in a downward direction. As a consequence, the eflciency of separation is low and extensive recirculation is necessary to attain an efifective concentration of the desired residue.

In accordance with the present invention, such effective concentration of the desired residue, which may be iron ore, for example, is eifected by maintaining the tailings, such as silica, for example, separated from the charge in an upper compartment of an inclined endless conveyor, separated from the charges in such succeeding compartment in a downward direction. Spec fically, the tailings from each compartment are washed or sluiced into one or more downwardly travelling tailing streams flowing parallel to the upwardly travelling stream of charges and concentrates. As a result, a high eflciency of concentration is efiected on a single pass and the amount of recirculation required is reduced to a negligible value.

In a preferred embodiment of apparatus for performing the invention, an endless belt conveyor is provided with rifles on its outer surface extending only part way thereacross so as to leave unrifled flow sections along each side of the rifled intermediate section. The conveyor is inclined and its upper run is supported on rollers so disposed as to maintain the lower end of the upper run substantially flat and the upper end with a relatively deep trough shape, the trough progressively flattening or becoming more shallow from the upper to the lower end.

Each rifle comprises a short upper section extending laterally of the belt, diagonally extending sections extending downwardly from each end of the upper section, and short legs extend from the ends of the diagonals parallel to and substantially spaced from the belt edges. The longitudinal legs of each rifle extend to within a short distance of the corresponding legs of the next lower rifle to leave gates for flow of tailings out of each compartment formed by adjacent rifles.

The material to be concentrated is discharged onto the 2,930,484 Patented Mar. 29, 1960 upper run of the conveyor just above its lower end, and the water flows over substantially the entire length of the upper run. The water washes out the tailings which flow through the gates onto the unrifled side portions of the belt. As the material moves up the conveyor path, with the trough progressively deepening, the heavier particles become more concentrated. There are two streams of downwardly moving tailings on the sides of the upwardly moving heavier residue retained by the rifling and troughs.

The tailings are discharged from the lower end of the conveyor and may be recirculated with or without intervening screening if desired. The concentrated residue is discharged from the upper end of the container. Efiective concentration is attained by proper selection and coordination of the speed and slope of the conveyor, and both these factors are made adjustable without interrupting operation of the conveyor.

For an understanding of the invention principles, reference is made to the following description of a typical embodiment thereof as illustrated in the accompanying drawing.

In the drawing:

Fig. 1 is a side elevation view of apparatus embodying the invention;

Fig. 2 is a top plan view of the endless belt conveyor;

Figs. 3 and 4 are transverse sectional views on the correspondingly numbered lines of Fig. 1; and

Fig. 5 is a partial upper plan view of the conveyor illustrating a modified form of rifle.

Referring to the drawings, the apparatus comprises an elevated supporting framework on which is mounted an endless belt conveyor 30. As best seen in Fig. 1, framework 10 includes uprights 11 and 12 interconnected by longitudinal braces 13. The upper ends of uprights 11 are pivoted to conveyor support beams 14. Uprights 12 have pivoted thereto arms 16 adjustable by a jack or the like engaged between braces 13 and outer ends of arms 16. Movable uprights 17 are pivoted at their upper ends to beams 14, and their lower ends are pivoted to arms 16 intermediate the ends of the latter. By means of elements 15, 16 and 17, the angle or slope of conveyor support beams 14 may be adjusted during operation of the conveyor.

Conveyor 30 is an endless flexible belt trained over rollers or drums 31 rotatably supported on beams 14. One drum 31 may be driven by a variable speed motor so that the conveyor speed may be adjusted during operation. A hopper 20 for unconcentrated material is arranged to discharge this material onto conveyor 30 near the lower end thereof, and a valved supply pipe 21 discharges water onto the upper end of the conveyor to flow downwardly thereover and separate lighter tailings from the heavier concentrates. The separated tailings fall into a hopper 22 at the lower end of the conveyor, from which they may be recirculated, or screened and then recirculated as indicated at 23, in any desired manner to hopper 20 if further separation is desired. The heavier concentrates retained on the upper run of the conveyor are discharged into a trough 25 supported on a framework 24 (only partly illustrated).

Referring to Figs. 2 and 5, the outer surface of conveyor is formed or provided with rifles or 35' at substantially uniformly spaced intervals therealong. As shown in Fig. 2, each rifle comprises an upwardly bowed central section 36 from the ends of which extend diagonal sections 37 in a trailing direction. Legs 38 extend from the ends of sections 37 in spaced parallel relation to the side edges of the conveyor. It will be noted that the rifles 35 are slightly nested or overlapped, in that the ends of legs 38 of each rifle are spaced only a short distance from the legs 38 of the subjacent rifle.

This provides gates 40 for the tailings to flow laterally onto unrilfied flow paths 45' extending along each edge of the conveyor.

. In the modified rifliing arrangement of Fig. 5, center section 36 is straight instead of bowed. While this ar rangement provides a larger setting area than does that of Fig. 2, it has the disadvantage that some of the tailings, such as silica in iron ore, is trapped thus decreasing the separation effect as compared to the arrangement of Fig! 2.

Referring to Figs. 3 and 4, the upper run of conveyor 30 is supported on rollers which impart a transverse profile thereto progressively varying from a deep trough shape at its upper end to a flat shape at its lower end. As seen in Fig. 3, the trough shape is imparted by sets of three rollers 41, 42, 42, roller 41 having a horizontal axis and rollers 42 an inclined axis. Roller support members 43 extend between beams 14. The flat lower part of the upper run is provided by mounting rollers 41', 42', 42' coaxially, although a single roller may be used.

In actual practice, the preferred speed of conveyor 30 is 50 feet per minute, and the preferred slope is 1.25 inches per foot. The water from pipe 21 flows over the material, separating the lighter tailings and sweeping these laterally through gates 40 onto unrifliled flow paths 45. The disposition of the riffling, and the gates 40, prevent reentry of the separated tailings into the central compartments. The concentration is facilitated by the progressively varying lateral contour of the upper run. The

gradual flattening of the belt toward its lower end proso vides an inverted Y effect to prevent the wash water affecting fresh material discharged from hopper 20. The net effect is that of two downflowing side streams in paths 45 divided by an upwardly moving mass of material undergoing concentration.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the invention principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

1. Apparatus for concentrating desired .values of crushed or ground materials comprising, in combination, a relatively elongated endless flexible belt conveyor having an upward inclination in the direction of movement of its upper run; riffles extending partly across the outer surface of said conveyor at substantially uniformly spaced intervals longitudinally thereof; each rifile comprising a central section extending substantially laterally of the conveyor and terminating substantially short of the side edges thereof, and at least one end section extending from an end of the central section in a trailing direction along the conveyor in spaced relation to the side edge of the conveyor and terminating in longitudinally spaced relation to the end section of the subjacent rifile; the outer surface of said belt being smooth except for such riffies whereby there is an unriilled flow path extending along the side edge of the conveyor; means for discharging unconcentrated material onto said upper run adjacent the lower end thereof for upward movement by engagement with said rilfles; and means for directing water onto said upper run adjacent the upper end thereof to wash over the material thereon and wash out the lighter tailings to flow laterally between adjacent riflles onto said unriflled flow path and down the latter.

2. Apparatus for concentrating desired values of crushed or ground materials comprising, in combination, a relatively elongated endless flexible belt conveyor having an upward inclination in the direction of movement of its upper run; rilfles extending partly across the outer surface of said conveyor at substantially uniformly spaced intervals longitudinally thereof; each rifile comprising a central section extending substantially laterally ly spaced relation to the end section of the subjacent riffle;

the outer surface of said belt being smooth except for such rifllcs whereby there is an unritlled flow path extending along the side edge of the conveyor; means for discharging unconcentrated material onto said upper run adjacent the lower end thereof for upward movement by engagement with said rifiles; means for directing water onto said upper run adjacent the upper end thereof to wash over the material thereon and wash out the lighter tailings to flow laterally between adjacent riflles onto said unriffled flow path and down the latter; and means imparting to the upper run of said conveyor a transverse contour varying progressively from a relatively deep trough shape at its upper end to a relatively flat shape at its lower end.

3. Apparatus for concentrating desired values of crushed or ground materials comprising, in combination, a relatively elongated endless flexible belt conveyor having an upward inclination in the direction of movement of its upper run; riflles extending partly across the outer surface of said conveyor at substantially uniformly spaced intervals longitudinally thereof; each riflle comprising a central section extending substantially laterally of the conveyor and terminating substantially short of the side edges thereof, and end sections extending from each end of the central section in a trailing direction along the conveyor in spaced relation to the side edges of the conveyor, longitudinally overlapping the central section of the subjacent rifile, and terminating in longitudinally spaced relation to the end sections of the subjacent riffle; the outer surface of said belt being smooth except for such riflles whereby there are unrifiied flow paths extending along the side edges of the conveyor; means for discharging unconcentrated material onto said upper run adjacent the lower end thereof for upward movement by engagement with said riifies; and means for directing water onto said upper run adjacent the upper end thereof to wash over the material thereon and wash out the lighter tailings to fiow laterally between adjacent riflles onto said unrifiled flow paths and down the latter.

4. Apparatus for concentrating desired values of crushed or ground materials comprising, in combination, a relatively elongated endless flexible belt conveyor having an upward inclination in the direction of movement of its upper run; riflles extending partly across the outer surface of said conveyor at substantially uniformly spaced intervals longitudinally thereof; each rilfie comprising a central section extending substantially laterally of the conveyor and terminating substantially short of the side edges thereof, and end sections extending from each end of the central section in a trailing direction along the conveyor in spaced relation to the side edges of the conveyor and terminating in longitudinally spaced relation to the end sections of the subjacent riille; the outer surface of said belt being smooth except for such riffles whereby there are unriflled flow paths extending along the side edges of the conveyor; means for discharging unconcentrated material onto said upper run adjacent the lower end thereof for upward movement by engagement with said rifiles; means for directing water onto said upper run adjacent the upper end thereof to wash over the material thereon and wash out the lighter tailings to flow laterally between adjacent riifies onto said unriflled flow paths and down the latter; and means imparting to the upper run of said conveyor a transverse contour varying progressively from a relatively deep trough shape at its upper end to a relatively flat shape at its lower end.

5. Concentrating apparatus as claimed in claim 3 in which the riflle end sections comprise intermediate secof the conveyor and terminating substantially short of l ons extending diagonally from the ends of the central sections and leg sections extending from the ends of the intermediate sections substantially parallel to the side edges of the container.

6. Concentrating apparatus as claimed in claim 3 in which said central rifile sections are bowed in the direction of movement of the conveyor.

7. Concentrating apparatus as claimed in claim 5 in which said central riflie sections are bowed in the direction of movement of the conveyor.

8. Concentrating apparatus as claimed in claim 4 in which said contour imparting means comprises rollers supporting said upper run at spaced intervals longitudinally thereof.

9. Concentrating apparatus as claimed in claim 3 including a supporting framework for said conveyor adjustable to vary the slope of the latter.

References Cited in the file of this patent UNITED STATES PATENTS Norton Dec. 31, 1907 Brooks June 6, 1911 Reimel et al Dec. 1, 1942 Finney Mar. 18, 1947 Hackney et al Mar. 4. 1958 FOREIGN PATENTS Germany Apr. 15, 1952 Germany Aug. 23, 1956 

1. APPARATUS FOR CONCENTRATING DESIRED VALUES OF CRUSHED OR GROUND MATERIALS COMPRISING, IN COMBINATION, A RELATIVELY ELONGATED ENDLESS FLEXIBLE BELT CONVEYOR HAVING AN UPWARD INCLINATION IN THE DIRECTION OF MOVEMENT OF ITS UPPER RUN, RIFFLES EXTENDING PARTLY ACROSS THE OUTER SURFACE OF SAID CONVEYOR AT SUBSTANTIALLY UNIFORMLY SPACED INTERVALS LONGITUDINALLY THEREOF, EACH RIFFLE COMPRISING A CENTRAL SECTION EXTENDING SUBSTANTILLY LATERALLY OF THE CONVEYOR AND TERMINATING SUBSTANTIALLY SHORT OF THE SIDE EDGES THEREOF, AND AT LEAST ONE END SECTION EXTENDING FROM AND END OF THE CENTRAL SECTION IN A TRAILING DIRECTION ALONG 